Generally, a gas insulated switchgear is configured with necessary devices such as breakers, disconnectors and main buses disposed in a metal container charged with insulation gas such as SF6 (sulfur hexafluoride) gas, which is excellent in insulating performance and arc-extinguishing performance. The gas insulated switchgear is used in an electric power station such as a transforming station or a power generating station.
Patent Literature 1 describes a so-called 1·½ CB (Circuit Breaker) system gas insulated switchgear having three breakers arranged and connected between a pair of main buses. Specifically, first to third breakers are connected in series between the paired main buses while making axes of the breakers horizontal, and disconnectors are annexed to both sides of an upper portion of each of the breakers, respectively. The disconnectors are arranged to match the longitudinal direction of the disconnectors to match the axial direction of the breakers so that an operating direction of each of the disconnectors is equal to the axial direction of the corresponding breaker. Therefore, the breakers and disconnectors are arranged on one and the same plane. Furthermore, three units each including these three breakers are prepared for three phases, and these units are arranged in a direction orthogonal to the axes of the breakers.